The transport of objects from one place to another has been a challenge since ancient times. Storage of multiple objects also poses challenges. In addition to specialized buildings, shelves, and cupboards for storage and bucket loaders, fork lifts, trucks, carts, planes and ships for transport, pallets have been created.
Pallets can be thought of as a form of a moveable shelf or platform. Depending on the load to be moved, the construction of a pallet is critical to durability and performance. Further, it is desirable that a pallet be constructed such that a loaded pallet may be placed directly on the load of a pallet below without damaging the lower load. Some storage systems employ open racking of pallets which systems have additional requirements so that the pallets may be used in such a system.
In certain industries such as the food industry, the use of untreated wood pallets provides an entry and/or growth medium for bacteria, mold, fungus and other biological organisms which pose threats to food safety and reduce the durability of the pallet. It is also desirable to employ pallets that may be easily cleaned and recycled. Therefore, it would be desirable to employ a pallet made of material not vulnerable to such invasion, and easy to clean. Further, wood pallets are not as durable as plastic or metal pallets, and will swell and contract with atmospheric or working conditions, causing issues in their use for automated packaging lines.
In order to move the pallets and their loads, machines such as fork lifts need to be able to easily engage and lift the pallet and its load and easily disengage from the pallet after the pallet is positioned. Providing a pallet with features to provide ease of transport by forklift is, therefore, also desirable.
A problem with the use of pallets for moving and storing materials is what to do with a pallet when empty. They often are stacked but take up quite a bit of space and the stack's height is limited in order to prevent shifting and the possibility of a stack of pallets falling on someone. Adding to the danger, many present pallet designs are heavy in order to accommodate their intended uses, making their empty-stage storage and transfer both cumbersome and expensive.
Most present pallets bearing dynamic loads of 2,000 pounds or more are constructed of materials such as wood and/or metal. Others may be constructed of fiberglass and plastic. Although attempts have been made to use plastic pallets for similar loads, the designs of those pallets have been deficient in the amount of sag, and the pallet's durability and load-bearing capability. Those pallets that adequately address sag and bear adequate weight are often also heavier, requiring more materials to provide adequate functionality.
What was needed was a lightweight pallet capable of bearing a dynamic load of about 2,000 pounds or more, especially a pallet that can span a 42 inch or 44 inch open pallet rack. The pallet needed to be durable and easily stored, transported, and nested with other such pallets. Preferably, such a pallet would be a relatively low cost pallet. Pallets of different dimensions having these features would also be desirable. And if such a pallet having all of these general features could be constructed to withstand more than 8 shipping cycles before repair or replacement, and made using mostly, if not all, recycled materials, the advantages could be multiplied and far outdistance the presently used wood pallet.